This invention relates to a spraying apparatus, and, more particularly, to a spraying apparatus which includes a pair of masking discs for defining sharp edges to the sprayed material.
This invention is a variation of marking or spraying machines described in my previous patents--U.S. Pat. Nos. 3,485,206, 3,700,144, 3,796,353, 3,817,429, 3,871,557, 4,126,273, and 4,262,821.
British Patent No. 1,456,411 describes a paint spraying device which includes a pair of shields which are mounted on the axle of the sprayer for masking the paint and thereby defining a stripe. However, as more and more paint is sprayed onto these shields, the paint can accumulate to the point at which the paint drips from the shields onto the surface which is being sprayed. Also, since the shields are mounted directly on the disc axle, the shields will move up and down as the discs engage stones, uneven areas of the surface, or other objects which cause variations in the surface.
The invention provides an improved masking disc which includes a flange for retaining the paint which is sprayed onto the disc edge. The flange terminates in a radially inwardly extending retaining lip which provides a well for holding the paint within the flange. The edge of the flange is spaced from the surface which is being sprayed by a rim on the flange. The masking discs are mounted on an axle which is supported by the spraying apparatus for generally vertical movement. The wheels of the apparatus are mounted on separate axles, and the masking discs can move up and down independently as the wheels and the discs engage variations in the surface which is being sprayed.